Hydraulic transmission



Feb. 28, 1950 E. K. Foos 2,499,059

HYDRAULIC mnsurssron Filed Dec. 2s, 1944 2 Sheets-Sheet 2 Patented Feb. 2a, raso 2,499,859 HYDRAULIC TRANSMISSION Edwin E. Fons. Yellow Springs. Ohio Application December 23, 1944, Serial No.

15 Claims.

missions which are in more general use.

One of the problems which has not been suctiai simplicity.

In the automotive eld particularly, eiorts have been made by engineers for many years to construct transmissions which would shift gears response to load changes, and

(Ci. 'I4-732) 2 manifold pressure of internal combustion engines for this purpose.

In the automotive field particularly, it is often the driving wheels and the engine.

One disadvantage of mechanical transmissions has been the limitation of the transmission to a few gear ratios. In most automobiles the three- In the drawings the invention is illustrated by a construction involving three-gear ratios, but merely for purposes of illustration;

Fig. 1 is a vertical sectional view on the line v l-I of Fig. 2 taken longitudinally through a transmission embodyin the principles of my invention:

Fig. 2 is a vertical sectional view on the line 2-2 of Fig. 1 taken transversely through the clutch case, looking in the direction of the a r rows, with a portion of the vane support broken away;

Fig. 3 Ls a sectional view on the line 2-8 of Fis. 1:

Fis. 4 is a diagrammatic illustration of auto matic means for shifting gears; and

Fig. 5 is a cross section on the line i looking in the direction of the Referring now to ings Iii is a driving shaft which may by an'engine such as an automobile engine, II is a circular disk mounted fixedly upon the end of the shaft for rotation therewith from which 5-5 of Fig. arrows.

surface of which vanes I2 project forming an impeller. the operation of which is described more fully hereafter. The inner edges of the vanes I2 rotate in a circle concentric with the shaft IB. The showing of vanes found in the drawing is diagrammatic, because there are many vane sections and mountings that could be used; the precise type of vane section and the use oi' bracing therefor if desirable may be chosen by the engineer in view of the particular services to be performed by a particular installation of apparatus.

Mounted about the driving vanes I2 is a casing I5 having a gland I6 through which the shaft IB passes, and to which it is that casing and casing is longer cylinder Il rotate together. This than the vanes I2 in order that the vanes may be moved longitudinally therewithin. A gear shift lever I1 has a hand operated pawl I8 and ratchet I5 to hold it in selected position. Attached to this gear shift lever is a collar which is seated in an annular groove in the shaft IU. The shaft rotates within the collar and can be moved longitudinally by shifting the lever I1. When the lever is shifted the vanes I2 are moved longitudinally within the casing I5. Within the casing I5 is a body oi liquid 2| which may substantially fill the casing in some instances, and in other instances may be present in smaller amount, the general requirement being that enough be present during operation and the conditions of centrifugal force attendant thereon to cover the space between the vanes I2 and the blades which are hereinafter depth to which the blades upon their shape. Under all circumstances there should be sumcient liquid in the casing to give maximum eillciency of power transmission.

Through the end of the casing opposite the gland I5 and through the bearing iI1, which is sealed to prevent the escape of fluid, project three concentric shafts 3i, 4B, 50. On the inner end of the shaft 50 is mounted a wheel 5I bearing upon its circumference blades 52 which have edges 52 which rotate in a circle which is concentric with the shafts I2 and SII, and is close to the circle in whicy rotate the edges I3 of the varies I2. On the other end of the shaft 50 is keyed a gear 54 of comparatively small diameter. The shaft la is hollow and is mounted for rotation about the shaft 50 on bearings 55. its inner end the shaft III carries a wheel II havkeyed by keys I6' so 4 ing blades l2 corresponding to the blades 52. 0n its outer end the shaft Ill carries a gear M of larger diameter than the gear 54.

The hollow shaft 30 is mounted on and for rotation about the shaft lill by bearings 45. On its inner end the shaft 30 carries a. wheel 3l having blades 32 mounted upon its circumference. 0n its outer end the shaft 30 carries a gear 34 which is of larger diameter than the gear 44.

The casing I5 has been broken away at the left of Fig. l to indicate that it is of greater length than drawing space lets be shown. The casing is of sufficient length to permit the coinplete disengagement of blades and vanes by retraction of the vanes toward the left end of the casing, as shown in Fig. 1.

In order that the operation of the invention may be made plain, it should new be assumed that the gear shift lever i1 has been moved to the left end of the ratchet as shown in Fig. 1, so that the vanes I2 will not overlap any of the wheels. The motor is now started and the cas- Ifl, the disk II, and the vanes but being separated from the blades do not produce corresponding rotation in them. By moving the shift lever I1 to the second notch in the ratchet the lmpeller is caused to telescope the first hydraulically operated wheel 5I, the blades of which are driven from the varies through the thin body of hydraulic fluid that separates their edges; the space between these edges is very small and slippage between them is astonishingly low. There is thus provided in effect a. substantially positive driving connection between vanes and blades.

As the blades 52 and their carrying wheel 5I are rotated they turn the shaft 50 and the gear 5|. The gear 54 meshes with a gear 56 which is mounted on a driven shaft 50 by a unidirectional clutch 51 which may conveniently be of the free-wheeling type, or of any other well known type which gives a positive drive in one direction and free rotation between the gear and the shaft when, for example, the speed of the shaft exceeds the speed of rotation of the gear and in this instance that prescribed by the ratio of gears 54 and 56. As the gear 54 is turned the gear 56 and the shaft 5D will be turned and power may be taken off the shaft 60. The end of shaft 50 is mounted in bearings in a support lll. Shaft 60 is mounted in bearings l I.

If the operator now moves the gear shift lever forward to the position shown in Fig. 1 the driving vanes I2 will overlap blades 42 as well as blades 52, both of which will manner which has just been described. The hydraulically operated wheel Il, as it rotates under the driving impulse of the blades 42 turns the shaft 40 and the gear M. The gear I4 meshes with a gear 45 which is mounted on the shaft 60 by a unidirectional clutch lil similar to that numbered 5l. The gears M' and 46 are in a different ratio, and tend to drive the shaft 5|) faster than it is driven by gears 54 and 55. Consequently the unidirectional clutch in the gear 56 is thrown out of operating position and the shaft rotates freely within that gear. The fact that the gear 56 is also moving is not a detriment but a help. because it is moving in the same direction and reduces the friction between the shaft and the unidirectional clutch.

When the geai` shift lever I1 is moved to the last position on the right in Fig. 1 the vanes I2 are placed in driving relation to blades 32 as well as 42 and 52. As the blades 32 are rotated be driven in the i auch they turn the hydraulically operated wheel Il, the shaft lo and the gear 3l. The gear M meshes with a gear 38 which is preferably fixed to the shaft Iii by a mounting $1. This mounting i1 can be a unidirectional clutch like 41 and 51 to provide free-wheeling in all positions of the gear shift lever, which is very desirable for many uses. On the other hand, if the engine is to be used as a brake the connection ll should be fixed. through use of a key 36' keying the gear lt to the shaft B0. In that case the engine acts as a brake whenever the blades 32 are in operative relation to the vanes of the impeller. The ratio of gears Il and IB is different from that of gears Il and lli and gives a higher speed to the shaft Il. Therefore, in this position of the vanes. the shaft Iii is driven from the gear 36 and not from gears 46 or B6, the unidirectional `clutches of which permit the shaft 6I to rotate freely within them.

In this invention gear shifting is accomplished smoothly and without shock and without disengaging the motor. In shifting to a higher gear the higher gear chain takes control progressively as the vanas are moved over the blades. In going from a higher to a lower gear the reverse is true, the lower gear, being already in operation, takes over control of the shaft 60 as soon as control is relinquished by the higher gear. It is possible to use as many gears as one chooses in such a system, the only requirements being that additional concentric shafts with their driving and driven members be emplaced. and that the vanes be made of sufficient length to drive all of the blades.

When it is desired to operate the device automatically the shift lever il' is mounted without ratchet control and is connected on one side to a spring 1G which urges it in one direction and on the other side to a servo motor l1 which is operated by changes in manifold pressure due to variations in load. The servo motor acts against the spring to shift to a lower gear when the load increases, and yields to the spring when the load decreases so that a higher gear will be engaged. In this case the spring will shift the hydraulic clutch into high gear as soon as the load is removed from the servo motor by stopping the engine, thus providing that the engine will always be available as a brake when the engine is not running, or when it is running free in coasting down a hill. During automatic operation the clutch will always remain in engagement unless manually disengaged.

When it is desired to use a reverse gear a clutch mechanism is employed which comprises a support 80 having bearings Bi-BI in which are mounted shafts 50 and 60 respectively, the ends of which i3-84 are keyed for the reception of sliding clutch members 85-86. A clutch lever 81 is pivoted at 8B to clutch member 85, at Sil to a support attached to the frame of the machine and at 90 to the lower clutch member 8B. Amxed to the end of shaft 50 is a clutch member 9i and afilxed to the end of shaft 60 is a clutch member 92. When the mechanism is being driven through the shaft 60 the lever 81 is thrown to the right, as seen in Fig. l, so that the clutch member 85 does not engage clutch member 9| but clutch member 86 does engage clutch member l2. Drive therefore is transmitted through these clutch members to shaft B0. When it is desired to throw the machine into reverse the clutch lever 81 is thrown to the position shown in Fig. 1 so that the shaft 50' is driven by the shaft 6 it and transmits its motion to a gear ill which is keyed to shaft Il' and meshes with a gear ill mounted upon shaft |02 carried by support Il.

The gear lli meshes with a gear lill which is keyed to the shaft Il' which is driven in reverse. Inasmuch as the higher ratio wheels II--II and their gear trains are running free because of the disengagement of clutch 88-92 all the driving effect of the vanes is directed through the wheel Bi. The lever l1 may be foot operated in an automobile or hand operated as desired.

This invention embodies not only the advantages which have been implied in the recitation of the objects of the invention but additional advantages springing from the nature of the hydraulic clutch itself apart from its connection to gears. This clutch is smooth but positive in operation, performing its functions without the Jerk which is unavoidable in mechanical clutches. It is adaptable to driving a single shaft without a gear shift or to the driving of any number of shafts, as hereinbefore explained.

A particular advantage of the invention is that the gears of a multiple ratio transmission are all continuously in engagement and need not themselves be shifted. The arrangement of unidirectional clutches in the gear box, as above described, contributes materially to the exibility of the device and the accomplishment of the objects of the invention.

Another advantage of the invention is that the ordinary flywheels and clutch mechanisms of standard automobiles may be done away with. The casing and the rotating body of fluid have enough inertia to perform the function of a flywheel, and the hydraulic clutch replaces the intricacies of the mechanical clutch and gear box with a simpler and more efiicient unit which requires no sliding gears for gear shifting.

As many widely different embodiments of this invention may be made without departing from a spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments which have been described in this specification except as defined in the appended claims:

l. A variable speed power transmission comprising a driven shaft. means to drive the shaft at different speeds comprising gears operably connected thereto, means to drive the gears comprising hydraulically operated wheels having cireularly arranged blades, means to drive the wheels comprising an impeller having vanes operable close to said blades, means to alter the relation of the impeller vanes to the blades of the wheels, and a liquid means for transmitting power from the vanes to the blades.

2. A variable speed power transmission cornprising a driven shaft, means to drive the shaft at dilferent speeds comprising gears operably connected thereto by unidirectional clutches. means to drive the gears comprising hydraulically operated wheels having circularly arranged blades, means to drive the wheels comprising an impeiler having vanes operable close to said blades. means to alter the relation of the impeller venes to the blades of the wheels, and means for enclosing said blades and vanes containing a liquid for transmitting power from the vanes to the blades.

3. A variable speed power transmission comprising a driven shaft, means to drive the shaft at different speeds comprising high and low speed gears operably connected thereto whereof the high speed gear is xediy connected to the shaft and each other gear is operably connected to the shaft by a unidirectional clutch, means to drive the gears comprising hydraulically operated wheels having circularly arranged blades, means to drive the wheels comprising an impel- 1er having vanes operable close to said blades, means to alter the relation of the impeller vanes to the blades of the wheels, and means to transmit power from the vanes to the blades comprising a liquid.

4. A variable speed power transmission comprising a driven shaft, means to drive the shaft at diierent speeds comprising high and low speed gears operably connected thereto, means to connect the low speed gears to the shaft in driving relation comprising unidirectional clutches, means to drive the gears comprising rotatable wheels having circularly arranged blades, means to drive the wheels comprising an impeller having vanes operable close to said blades, means to alter the relation of the impeller vanes to the blades of the wheels, and a casing containing driving fluid in which are mounted said blades and vanes.

5. A variable speed power transmission comprising a driven shaft, means to drive the shaft at different speeds comprising gears operably connected thereto by unidirectional clutches, means to drive the gears including rotatable wheels operably connected thereto. said wheels having circumferentially arranged blades, means to drive the wheels comprising an impeller having vanes operable close to said blades, means to alter the relation of the impeller vanes to the blades of the wheels, and a casing housing said blades and vanes containing a fluid adapted to transmit power from the vanes to the blades,

6. A variable speed power transmission cornprising a driven shaft, means to drive the shaft at different speeds comprising gears separately mounted thereupon by unidirectional clutches, means to drive the gears comprising intermediate gears mounted upon concentric shafts, said shafts bearing hydraulically operated wheels having circumferentially arranged blades, means to drive the wheels comprising an impeller having varies rotatable about the blades, means to move the impeller blades into and out of operative relation to the blades, and means to transmit power from the vanes to the blades comprising a liquid.

7. A variable speed power transmission comprising a driven shaft, means to drive the shaft at diierent speeds comprising gears operably connected thereto by means comprising unidirectional clutches, means to drive the gears including hydraulically operated wheels having circumferentially arranged blades, an impeller having circularly arranged vanes, means to telescope the impeller and wheels, and means to transmit power from the impeller to the wheels comprising a liquid.

8. A variable speed power transmission comprising a driven shaft, means to drive the shaft at different speeds comprising gears operably connected thereto by means comprising unidirectional clutches, means to drive the gears including rotatable wheels having circumferentially arranged blades having circularly arranged outer edges, means to drive the wheels comprising an impeller having vanes with circularly arranged inner edges, the circles of said vane and blade edges being of slightly different radius, means to move the impeller into driving relation to each of the wheels, and means to transmit power 8 from the impeller to the wheels comprising a liquid.

9. A variable speed power transmission comprising a driven shaft, means to drive the shaft at different speeds comprising gears operably connected thereto by means comprising unidirectional clutches, means to drive the gears comprising hydraulically operated wheels having circumferentially arranged blades, means to drive the wheels comprising a driving shaft, a disk mounted thereupon. vanes projecting from said disk in circular arrangement, means to move said vanes into driving relation to said blades, and a rotatable casing enclosing said vanes and blades containing a liquid adapted to transmit power from the vanes to the blades.

l0. A power transmission apparatus comprising a rotatable casing. circularly arranged vanes within the casing, means to move the vanes longitudinally ci' the casing, means to rotate the casing and the vanes. a rotatable shaft passing through the casing, blades operably mounted on the shaft in proximity to the vanes, and means to transmit power from the vanes to the blades comprising a liquid.

l1. A power transmission apparatus comprising a rotatable casing containing a driving liquid, circularly arranged vanes within the casing, means to move the vanes longitudinally of the casing, means to rotate the casing and the vanes, and means to transmit power from the vanes which comprises rotatable concentric shafts, blades mounted on said shafts for rotation in proximity to said vanes, and gear trains of different ratio driven from said shafts and operably connected in driving relation to a single shaft.

12. Power transmission means comprising a driving and a driven shaft, and means to transh mit motion between them comprising a hydraulic clutch having a casing containing driving uid, a plurality of circularly arranged varies within said casing connected to the driving shaft, a plurality of hydraulically actuated wheels adjacent to said varies within the casing. a plurality of gear trains operably connected to said wheels to drive the driven shaft, and means for moving the varies longitudinally with respect to the wheels to select a particular gear train for driving the said driven shaft.

13. A transmission comprising a plurality of gears operably connected to a shaft by unidirectional clutches, a hydraulic clutch comprising a casing containing a driving iiuid, circularly ar ranged vanes within the casing, means for rotating the vanes, hydraulically actuated wheels adjacent to said vanes within the casing, one of said wheels operably connected to each said gear, and means for moving the varies longitudinally with respect to the wheels to selectively activate said gears to drive the shaft.

14. A power transmission mechanism comprising a driven shaft, a driving shaft, a rotatable casing mounted on the driving shaft containing driving fluid, an impeller within the casing in driven relation with said driving shaft, a plurality of hydraulically driven wheels mounted within the casing, concentric shafts extending through said casing, each of the said wheels being individually mounted on and keyed to one of the concentric shafts, means for eil'ecting reiatlve axial movement of said impeller and wheels, gear trains of different ratios connecting said concentric shafts to the driven shaft. and unidirectional clutches connecting all of the said gear trains to the driven shaft with the excep-l tion of the gear train providing the highest speed to the driven shaft for a given speed oi the driving shaft.

15. A power transmission mechanism comprising a driven shaft, an intermediate shaft, a driving shaft, a rotatable casing mounted on the driving shaft containing driving fluid, an impeller within the casing in driven relation with said driving shaft, a plurality of hydraulically driven wheels mounted within said casing, concentric shafts extending through said casing, each said wheel being individually mounted on and indriven relation with one of said concentric shafts, means for effecting relative axial movement of said impeller and wheels, gear trains of different ratios connecting the concentric shafts to the intermediate shaft, unidirectional clutches connecting all of the gear trains to the intermediate shaft with the exception of the gear train providing the highest speed to the intermediate shaft for a given speed of the 10 driving shaft, a reversing gear train, and manually controlled clutches for eiiectively selective connections between the intermediate shaft and the driven shaft and between said reversing gear train and one of the concentric shafts.

EDWIN K. FOOS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,551,055 Rieseler Aug. 25. 1925 1,672,232 Saives June 5, 1928 1,778,365 Littlejohn Oct. 14, 1930 2,055,895 Fawcett Sept. 29, 1936 2,297,259 Speiser Sept. 29, 1942 2,318,660 Barrett May 11, 1943 2,321,226 McKay June 8, 1943 2,322,479 Schjolin June 22, 1943 Wilhelmy Sept. 16, 1947 

